Photographic color developer compositions are used for processing color photographic film or paper providing an intended image. In general, such a composition contains a color developing agent as a reducing agent, for example, 4-amino-3-methyl-N-(2-methanesulfonamidoethyl)aniline, forming an intended dye upon reaction with a dye forming coupler. U.S. Pat. Nos. 4,892,804, 4,876,174, 5,354,646 and 5,660,974 describe various color developer compositions.
To replenish processing components which have been consumed in reaction or carried out by processed photographic material, color developer replenishing solution is supplied to color developing solution in a color developing tank. Such replenishment is designed so as to maintain a prescribed developing level and stability of the color developing agent.
A color developer replenishing solution is supplied in the form of at least three separate parts (or concentrated compositions), which are usually mixed immediately before use thereof. Separate plural parts are often supplied to maintain chemical activity and solubility of ingredients. Stocking these together under alkaline conditions results in deterioration or undesired reaction with each other. The parts are comprised of one containing a color developing agent, another one containing material to keep alkalinity and yet another one containing a compound such as an antioxidant. A homogeneous color developing solution can usually be obtained by mixing all of these parts with water.
In the photographic industry, reducing the number of such parts used for preparation of the replenishing solution has been desired to reduce troublesome handling. Solutions ready to use as such, so-called ready-to-use type solutions, concentrated compositions or powdery mixtures are commercially available in the field of this technology. For example, EP-A No. 0793141 (hereinafter, the term EP-A refers to a European Patent Application Publication) describes a color developer composition comprised of two parts, which can be supplied in the form of a solid or a liquid.
To provide optimum processing performance, it is generally known that concentration of ingredients of a processing solution in a processing tank must be respectively maintained within a prescribed range. The most important solvent in such photographic processing is water. Accordingly, solubility in water is an important factor for an inorganic salt and an organic salt.
In these ready-to-use type solutions, which are superior in handlability, all of the ingredients are made to objective concentrations and consequently a large amount of water is contained therein, resulting in increased costs of manufacture, transport and storage.
In the photographic industry, therefore, it is desired to provide a photographic processing composition in a concentrated form (including a color developer composition) so that a manufacturer or user has no necessity of great cost of transport or storage of a large amount of water, thereby rendering a smaller container to be usable. In the photographic industry is further desired a composition which is usable immediately after taking out from the container (for example, known as an automatic replenishing processor), without necessity of mixing various ingredients (thereby reducing errors in mixing).
Comparing a liquid concentrate with a solid mixture (e.g., powder, tablet), the liquid concentrate is convenient in usage but is more expensive for packaging relative to the solid mixture. Although powder can be highly concentrated, it is difficult to supply stable powder to respective photographic chemical compositions. Further, powder has problems such as dust, necessity of separately packaging and complicated operations for measuring and mixing. Furthermore, it takes a lot of labor and time to complete dissolution into a uniform solution state.
Another concentration form known in the art is paste or a slurry of chemicals, as described in EP-A No. 0204372 and 0800111. Such a mixture has defects such as insufficient uniformity and delayed dissolution of solid components.
Conventional “plural part type” used to provide a color developer composition is apt to be considered that mixing all components forms a single homogeneous composition. In such a concentrated form, however, interaction between chemicals and deterioration thereof are marked, adversely affecting processed photographic material and resulting in deteriorated image quality which are unacceptable in practical use.
Recently, to overcome the foregoing problems, a single part type color developer composition (single mixture) has been commercially available. However, precipitates (such as slurry) or plural solvent phases exist in such a composition so that it is necessary to conduct sufficient stirring or mixing prior to use.
Accordingly, there has been strongly desired a single part type color developer composition (a single mixture) which is homogeneously and stably concentrated. Such a concentrated composition not only reduces the cost of transporting a solution diluted with a large amount of water and to stock the solution but also eliminates the necessity to mix plural parts or stir plural phase compositions, providing a product attractive to user.
In conventional systems for processing color negative film using hydroxyalkyl-substituted p-phenylenediamine type color developing agents, it has been supposed that forming a single part is difficult and plural parts are almost mandatory.
Since it is required to control development stability, hydroxylamine salts used as an antioxidant for color developing agents greatly affect developability and it is necessary to pay close attention for consumption and oxidative decomposition thereof.
In color developer composition kits for color negative film, hydroxylamine salts are supplied separately from other ingredients, or an antioxidant other than hydroxylamine salts is used to form a single part.
JP-A No. 2001-100380 (hereinafter, the term JP-A refers to a Japanese Patent Application Publication) exemplarily describes the use of preservatives other than hydroxylamine salts. However, a color developer solution not using hydroxylamine salts differs in basic development activity, resulting in problems of development quality.
JP-A No. 2000-314948 describes the use of a hydroxylamine salt in a single part (a single liquid kit), as a comparative example of the invention, pointing out problems in storage stability. It was further proved by the inventors of this application that there were problems that developability was varied after being aged at a relative high temperature.
JP-A Nos. 8-314092 and 9-68785 discloses a one-part type color developer replenishing solution, which is preserved in a packaging material having a specified oxygen permeability. The invention described in this disclosure concerns a technique in which the use of a not concentrated, working solution type replenisher in process photographic materials, specifically a photographic material having a magnetic recording layer results in enhanced magnetic readability. However, it was proved that keeping a concentrate type replenishing solution having a relatively high color developer concentration at high temperature over a long period of time tended to cause tarry deposition in a kit or a replenishing tank, often causing uneven development when using this replenishing solution in process of photographic material.